Continuous systemic perfusion via collaterals at moderate hypothermia in aortic arch repairs in neonates.

AIM

To present our experience with modified cannulation with continuous, moderately hypothermic systemic perfusion in extensive aortic arch repair. The technique has fewer complications and preserves cerebral blood flow autoregulation.

METHOD

Nine neonates, 6 with the hypoplastic left heart syndrome and 3 with the interrupted aortic arch with ventricular septal defect, were surgically treated with this technique between June and December 2001. Before extracorporeal circulation, 3.5-mm polytetrafluoroethylene tube was sutured onto the innominate artery and the arterial perfusion cannula inserted into the tube. Aortic arch repair was then performed with extracorporeal circulation. Right radial artery and femoral artery pressures were continuously monitored. Perfusion flows were built up gradually, with strict attention to the upper body (right radial artery) pressures not to exceed normal values. Procedures were carried out at moderate hypothermia (>28 degrees C), preferably with the beating heart.

RESULTS

No morbidity or mortality attributable to continuous perfusion occurred. Mean+/-SD extracorporeal circulation duration was 114+/-26 min. Maximum perfusion rate (actual/required flow for body surface area) was 1.65 at normal perfusion pressures. Right radial artery pressure at full flow (2.2 L/m2/min) was 56.1+/-6.7 mm Hg, whereas femoral artery pressure was 34.2+/-8.2 mm Hg. Decrease in right radial-to-femoral artery pressure was 21.9+/-5.6 mm Hg. The lowest nasopharyngeal temperature was 28.5 degrees C. There were no neurologic complications.

CONCLUSION

Continuous, moderately hypothermic systemic perfusion via collaterals seems to be a method of choice in aortic arch repair in neonates. As there is no need for deep hypothermic total circulatory arrest, its numerous sequelae, such as increased postoperative bleeding and permanent neurologic deficit, can be avoided.